Corning Pyrex 5640-100 Borosilicate Glass 100mL +/- 0.08mL Flat Bottom Class A Heavy Duty Volumetric Flask, with Glass Standard Taper Stopper (Pack of 6) Capacity: 100mL; height: 181mm; outer diameter: 60mm; tolerance: +/- 0.08mL Made from borosilicate glass code 7740 Flat bottom volumetric flask has a No. 13 standard taper stopper made from hollow glass - and a long neck style Flask provides improved lab convenience - broad selection - and precise volume measurement Manufactured to Class A tolerances as established by ASTM E-694 - ASTM E-542 - and ASTM E-288